Digital impressions have turned one of the most complicated and error prone procedures in dentistry into one of the most predictable treatments we can provide.
When taking a physical impression of an impression abutment, you need to secure it to the PVS material so it remains rigid during pour ups. Some choose open trays while others prefer closed trays. When you deal with multiple units, their divergence or convergence can inadvertently lock the tray in the patient’s mouth. Sometimes, the impression abutments impinge on each other and keep you from seating them all the way.
That was a short list of the many things that can go wrong. With a digital impression, you can capture the contacts or the adjacent teeth, the opposing, and the tissue profile very easily. You can then place a scan-body and take an impression of it’s position and identify the location of the fixture.
In the following videos you can see the steps involved and how easy it is to manage the impression and accurately capture the implant location.
In titanium blanks, there is only one place to put the sprue, which is on the occlusal. One might think that this is would be easier to manage, but the trouble is that the titanium blank is cylindrical in shape, and it makes it difficult to keep track of the implant hex position and proper indexing.
There is one important matter to keep in mind when digitally designing an implant abutment for milling from a pre-milled blank. Unlike regular restorations you can design a restoration in (CAD software) and position it in a block , place a sprue in a desired position, and mill (CAM software) the final product.
The solution is to provide data to the milling machine so that it can properly index the titanium blank. To keep it simple, a regular restoration can just be milled from a designed stl file. The titanium pre-milled blanks need accompanying files to the designed stl to properly mill the abutment for indexing purposes. In exocad software, there is a construction file that accompanies the design and the CAM software can read both files and produce a desired result.